You can get the cars original factory order form by applying to porsche.  But, i believe the PCGB now offer this service to members for free. 
email PCGB HQ and ask. 


having owned and restored a few 356. I would say unless it is a very special/rare car then i would just go with the colour you like.  in the past i have gone to great length to restore a 356c to its original specifications. Only to find when i sold it the new owner changed everything… 

Hi Philip, what Helen says about originality is correct and if you particularly want the car to be as original as possible, then you should have the book titled :-
The 356, A Restorers Guide to Authenticity, by Dr Brett Johnson. ISBN 0-929758-16-1.
This lists Silver Cabrio's made by Reutter, would have as standard, either Red or Blue leather seats, but is not specific about the exact colour. 
 
Unfortunately Porsche have stopped issuing the Certificates of Authenticity and finding out exactly what your car was finished with when it left the factory, is not easy and may be quite expensive to get. It seems to be down to Data Protection laws in Germany.
 
You should email Fred Hampton on 356@porscheclubgb.com sending him your chassis number, to see if PCGB has any record of the details.
Robin
 

Hi Philip 
Lots of great info above.  When restoring  my C coupe I had some interior work done.  I found the correct vinyl but had to send it to Germany to get the correct perforation holes stamped.  No machine with the correct pattern exsist in the UK.   I have extra copy of the restorers guide, pm me if your interested.

All Porsches prior to early 1970 have something called a Kardex, effectively it’s factory birth certificate. They typically list original engine and gearbox numbers, paint, trim, chosen options, etc etc, right down to key number for the glove box. A wealth of information. Porsche still have them but because they often list the original owner, they stopped making them generally available in the 1980’s I believe.
They replaced it with Certificates of Authenticity (CoA), which is what the club used to be able to get members for free. These aren’t regarded as being very reliable as errors in them are commonplace. Porsche stopped doing them a few years back, when it became apparent they were being used to fake matching numbers cars. They offer a couple of alternatives now, one extremely expensive and you have to take your car to a Classic Porsche Centre. The other gives limited information, although it might tell you about trim colour. But not if your car was say, a genuine S90, which substantially effects it’s value.
In summary, Kardex is king and the good news is, I can get hold of them. I know a guy, who knows a guy and have recently obtained them for my cars. What’s fantastic about them is how they can tell you about your car’s life story. Turns out my California black plate B T6 was originally delivered to Berlin in October 1961, as the Wall was going up and Russian and American tanks were yards apart. WW3 looked imminent and the German owner decided to high tail it out of there. Photos of it at R29 last meet at Fairoaks on the website.
When you decide on colour, I’d recommend a kit from Autos International Inc in California. A local trimmer would be able to do serviceable job, but not accurately. Love it or loath it, 356s are increasingly about authenticity and those guys seriously know their stuff. Google their website and see.

Hi Mike,
Am trying to email from NZ you but I think there is more after the [link=mailto:mike356@btinternet]mike356@btinternet[/link] word?? Unfortunately I don't know how to PM anyone? ( i'm sure someone will tell me how now!)
Regards
Tony.
Have now added .com at the end and it hasn't been returned ? yet?